docs: def _get_equivalent_distances_east(wid, lng, mag, repi, focal_depth=10.,
                                     ab06=False):
      """
      Computes equivalent values of Joyner-Boore and closest distance to the
      rupture given epoicentral distance. The procedure is described in
      Atkinson (2012) - Appendix A (page 32).
  
      :param float wid:
          Width of rectangular rupture
      :param float lng:
          Length of rectangular rupture
      :param float mag:
          Magnitude
      :param repi:
          A :class:`numpy.ndarray` instance containing repi values
      :param float focal_depth:
          Focal depth
      :param boolean ab06:
          When true a minimum ztor value is set to force near-source saturation
      """
      dtop = focal_depth - 0.5*wid
      # this computes a minimum ztor value - used for AB2006
      if ab06:
          ztor_ab06 = 21-2.5*mag
          dtop = np.max([ztor_ab06, dtop])
      ztor = max(0, dtop)
      # find the average distance to the fault projection
      dsurf = np.max([repi-0.3*lng, 0.1*np.ones_like(repi)], axis=0)
      # rrup
      rrup = (dsurf**2+ztor**2)**0.5
      # return rjb and rrup
      return dsurf, rrup